Throughout this application, various publications, patents and published patent applications are referred to by an identifying citation. The disclosures of the publications, patents and published patent applications referenced in this application are hereby incorporated by reference into the present disclosure.
Vortex flowmeters are commonly installed in-line within a process-fluid flow conduit to measure the rate of fluid flow therethrough. These meters are available in a wide range of sizes, e.g., to match the inner diameters (IDs) of various-sized conduits. Vortex flowmeters are available in a range of standardized sizes, including those having IDs of ½, ¾, 1, 1.5, 2, 3, 4, 6, 8, 10 or 12 inches.
Frequently, however, process-fluid flow conduits are oversized for the particular process flow requirements, such as to allow for anticipated future increases in demand. A consequence of this oversizing is that the fluid within this conduit, and within the bore of a matching vortex flowmeter, may be flowing at an undesirably low velocity. Those skilled in the art will recognize that low velocity may adversely affect the performance of the flowmeter.
One potential solution to this problem is to install smaller sized flowmeters into these relatively large size conduits, such as with reducers in the form of conically tapered flanges. However, the linearity of measurement tends to decrease as the bore size is reduced, and performance characteristics of reduced bore meters may result in degraded linearity and/or reduction of operating range for a given linearity (e.g., greater than a 1% variation over its range of operation) for many applications.
There is therefore a need to provide vortex flowmeters capable of providing accurate and relatively linear fluid flow measurements at reduced bore sizes.